Blue Ox user here...and a big fan of it.
(previous hitches include Equal-i-zer and Reece Dual Cam)
Sounds like you have some under steer...not enough transfer to the front wheels. What weight bars did the dealer set you up with?
Our trailer has a gross weight of 10,000 lbs and we have the 1400 lb. bars.
Don't be afraid to put A LOT of tension on the bars. They are designed for that and it's how they transfer weight and how they control sway.
You really need to load your trailer trip ready to get a feel for how it will behave.
The little wrench that came with the hitch is worthless. Get a 24 in. ratcheting breaker bar (Harbor Freight) for hooking and unhooking the chains.
Again, I really like the Blue Ox. I get no sway at all in lots of conditions and many many miles since we got it.